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<h4 class="subsection" id="S_002f390-Function-Attributes-1"><span>6.33.28 S/390 Function Attributes<a class="copiable-link" href="#S_002f390-Function-Attributes-1"> &para;</a></span></h4>

<p>These function attributes are supported on the S/390:
</p>
<dl class="table">
<dt><a id="index-hotpatch-function-attribute_002c-S_002f390"></a><span><code class="code">hotpatch (<var class="var">halfwords-before-function-label</var>,<var class="var">halfwords-after-function-label</var>)</code><a class="copiable-link" href="#index-hotpatch-function-attribute_002c-S_002f390"> &para;</a></span></dt>
<dd>
<p>On S/390 System z targets, you can use this function attribute to
make GCC generate a &ldquo;hot-patching&rdquo; function prologue.  If the
<samp class="option">-mhotpatch=</samp> command-line option is used at the same time,
the <code class="code">hotpatch</code> attribute takes precedence.  The first of the
two arguments specifies the number of halfwords to be added before
the function label.  A second argument can be used to specify the
number of halfwords to be added after the function label.  For
both arguments the maximum allowed value is 1000000.
</p>
<p>If both arguments are zero, hotpatching is disabled.
</p>
</dd>
<dt><a id="index-target-function-attribute-4"></a><span><code class="code">target (<var class="var">options</var>)</code><a class="copiable-link" href="#index-target-function-attribute-4"> &para;</a></span></dt>
<dd><p>As discussed in <a class="ref" href="Common-Function-Attributes.html">Common Function Attributes</a>, this attribute
allows specification of target-specific compilation options.
</p>
<p>On S/390, the following options are supported:
</p>
<dl class="table">
<dt>&lsquo;<samp class="samp">arch=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">tune=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">stack-guard=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">stack-size=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">branch-cost=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">warn-framesize=</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">backchain</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-backchain</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">hard-dfp</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-hard-dfp</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">hard-float</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">soft-float</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">htm</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-htm</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">vx</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-vx</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">packed-stack</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-packed-stack</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">small-exec</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-small-exec</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">mvcle</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-mvcle</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">warn-dynamicstack</samp>&rsquo;</dt>
<dt>&lsquo;<samp class="samp">no-warn-dynamicstack</samp>&rsquo;</dt>
</dl>

<p>The options work exactly like the S/390 specific command line
options (without the prefix <samp class="option">-m</samp>) except that they do not
change any feature macros.  For example,
</p>
<div class="example smallexample">
<pre class="example-preformatted"><code class="code">target(&quot;no-vx&quot;)</code>
</pre></div>

<p>does not undefine the <code class="code">__VEC__</code> macro.
</p></dd>
</dl>

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